Currently, multi-channel transmission of a signal is used in many application scenarios, and delays of output signals of multiple channels need to be consistent. For example, in a microwave communications system, a space diversity reception technology is usually used to cope with multipath fading. That is, two receive antennas, a main antenna and a diversity antenna, are disposed to independently receive a same signal. The signal received by the main antenna and the signal received by the diversity antenna are combined as one signal after delay alignment and other processing are performed on the signals. Then, a subsequent step such as demodulation is performed. That is, during microwave communication, a delay of an output signal from a receive channel of the main antenna and a delay of an output signal from a receive channel of the diversity antenna need to be consistent.
In the prior art, after an input signal delay difference between channels is detected, delay compensation is usually performed in a manner of manually connecting a cable of a corresponding length. For example, as shown in FIG. 1, on a first channel Ch1 and a second channel CH2, a delay of an input signal to the first channel Ch1 is less than a delay of an input signal to the second channel CH2. Therefore, a cable needs to be connected to the first channel CH1 to increase a delay of a signal transmitted on the first channel CH1, so that a delay of an output signal from the first channel CH1 and a delay of an output signal from the second channel CH2 are consistent.
However, in the solution in which delay compensation is performed by manually connecting a cable, not only a relatively high requirement is imposed on a technical level of implementation personnel, a device integration level is also relatively low because of a relatively large size of additionally connected cables.